#!/bin/sh

# provide the shortest possible unique hardware path to a block device
# for the udev persistent disk device naming scheme
#
# Copyright (C) 2005 SUSE Linux Products GmbH
# Author:
#	Hannes Reinecke <hare@suse.de>
#
#	This program is free software; you can redistribute it and/or modify it
#	under the terms of the GNU General Public License as published by the
#	Free Software Foundation version 2 of the License.
#
# to be called from a udev rule to return the name for a symlink
#	DEVPATH=/block/sda/sda3 path_id
#	path_id <devpath>

# examples for all block devices on a system:
#	for i in `find /sys/class/block`; do DEVPATH="`echo $i | sed -e 's@^/sys\|/dev@@g'`"; path_id; done

# SCSI cdrom
# /class/block/sr0 -> /devices/pci0002:30/0002:30:0c.0/host0/target0:0:0/0:0:1:0
# pci-0002:30:0c.0-scsi-0:0:1:0
#
# SCSI disk
# /class/block/sda -> /devices/pci0002:30/0002:30:0c.0/host0/target0:0:0/0:0:4:0
# pci-0002:30:0c.0-scsi-0:0:4:0
#
# SATA disk, 4 channels per controller
# /class/block/sda -> /devices/pci0001:00/0001:00:07.0/0001:05:0c.0/host0/target0:0:0/0:0:0:0
# pci-0001:05:0c.0-scsi-0:0:0:0
#
# IDE disk
# /class/block/hda -> /devices/pci0002:02/0002:02:0d.0/ide0/0.0
# pci-0002:02:0d.0-ide-0.0
#
# IDE cdrom on a Mac ASIC:
# /class/block/hdc -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.00020000:ata-3/ide1/1.0
# mac-io_ata-3_master
#
# IDE cdrom on a Mac ASIC, with ide-scsi:
# /class/block/sr0 -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.0001f000:ata-4/ide0/0.1/host2/target2:0:0/2:0:0:0
# mac-io_ata-4_slave

# USB CDrom drive without 'serial' number:
# reusing 'product' and 'manufacturer' string, if available
# /class/block/sr0 -> /devices/pci0001:00/0001:00:04.0/0001:02:0b.0/usb4/4-2/4-2:1.0/host4/4:0:0:0
# usb-storage-odd-Freecom-USIDERev930:0:0:0

# devices may have several interfaces on one PCI device, like IDE:
# pci-0001:00:04.0_ide1-master
# pci-0001:00:04.0_ide2-master
# pci-0001:00:04.0_ide2-slave
# they are marked as ports, it is expected that the driver shows
# ide1 even if there is nothing connected to either master or slave
# interface
#
# match order is important.
# first IDE to find ide-scsi devices, then SCSI
# first usb-storage, then firewire sbp2, then the rest

SYSFS=/sys
RESULT=1
TYPE=
OPWD="`pwd`"
full_sysfs_path=
full_sysfs_device_path=

if [ -z "$DEVPATH" -a -z "$1" ] ; then
    exit 1
fi

if [ -z "$DEVPATH" ] ; then
    case "$1" in
	$SYSFS/*)
	    DEVPATH="${1#$SYSFS}"
	    ;;
	*)
	    DEVPATH=$1
	    ;;
    esac
fi

if [ ! -e $SYSFS$DEVPATH/dev ] ; then
    exit 1
fi

case "$DEVPATH" in
    /devices/*)
	cd "$SYSFS$DEVPATH/subsystem";
	TYPE="`pwd -P`"
	cd "$OPWD"
	TYPE="${TYPE##*/}"
	;;
    /class/*)
	TYPE="${DEVPATH#/class/}"
	TYPE="${TYPE%%/*}"
	;;
    /block/*)
	TYPE=block
	;;
    *)
	exit 1
	;;
esac

get_port_offset () {
    local type offset port
    type=$1
    offset=$2
    for i in $type[0-9]* ; do
	: i $i
	port="${i#$type}"
	if [ "$port" -lt "$offset" ] ; then offset=$port ; fi
    done
    echo $offset
}

handle_pci () {
    local DEV=$1
    cd -P $1
    DEV=${PWD}
    pci_id=${DEV##*/}

    host_dev_path=$DEV
    while [ ! -z "$host_dev_path" ] ; do
	case "$host_dev_path" in
	    */pci[0-9]*)
                host_dev_path=${host_dev_path%/*}
		;;
	    *) break;;
	esac
    done

    d="pci-$pci_id-$d"
    D="$host_dev_path"
    RESULT=0
}

handle_block_ide () {
: handle_block_ide $*
	local DEV=$1
	local port idedev idecontroller
	# IDE
	: DEV $DEV

	port=${DEV##*/}
	idedev=${DEV%/*}
	idecontroller=${idedev%/*}
	# port info if the controller has more than one interface
	port="${port#ide}"
	: port $port d $d
	: idedev $idedev kernel_port $port
	case "${port#*.}" in
		 0)
		 channel=0
		 ;;
		 1)
		 channel=1
		 ;;
		 *)
		 echo "Error: $idedev is neither master or slave" >&2
	esac

	cd $idecontroller
	offset="`get_port_offset ide ${port%.*}`"
	cd "$OPWD"
	:  port offset $offset
	port=$((${port%.*} - $offset))
	if [ "$d" ] ; then
	    d="ide-${port}:$channel-$d"
	else
	    d="ide-${port}:$channel"
	fi
	D=$idecontroller
	RESULT=0
}

handle_block_scsi () {
    : handle_block_scsi $*
	local DEV=$1
	local cil controller_port controller_dev
	# SCSI device
	cil="${DEV##*/}"
	cil="${cil#*:}"
	target_dev=${DEV%/*}
	target_id=${target_dev##*/target}
	cd "$target_dev"
	target_num=0
	for tid in ${target_id}* ; do
	    target_num=$(( $target_num + 1 ))
	done

	controller_port=${target_dev%/*}
	controller_dev="${controller_port%/*}"

	: controller_dev $controller_dev
	: controller_port $controller_port
	# a host controller may have more than one interface/port
	controller_port="${controller_port##*/host}"
	#
	cd "$controller_dev"
	controller_offset=$(get_port_offset host $controller_port)
	cd "$OPWD"
	controller_port=$(( $controller_port - $controller_offset))
	scsi_id="scsi-${controller_port}:${cil}"

	if [ "$d" ] ; then
	    d="${scsi_id}-$d"
	else
	    d="$scsi_id"
	fi

	D="$controller_dev"
	RESULT=0
}

handle_block_firewire () {
    :handle_block_firewire $*
    local DEV=$1

    if [ -f "$D/ieee1394_id" ] ; then
	read ieee1394_id < $D/ieee1394_id
    fi
    
    if [ -z "$ieee1394_id" ] ; then
	: no IEEE1394 ID
	RESULT=1
	return
    fi

    fw_host_dev=${DEV%/fw-host*}
    # IEEE1394 devices are always endpoints
    d="ieee1394-0x$ieee1394_id"
    D="$fw_host_dev"

    RESULT=0
}

handle_block_fc () {
: handle_block_fc $*
	local DEV=$1
	local cil controller_port controller_dev
	# SCSI-FC device
	fc_tgt_hcil="${DEV##*/}"
	fc_tgt_lun="${fc_tgt_hcil##*:}"
	fc_tgt_path="${DEV%/*}"
	fc_tgt_num="${fc_tgt_path##*/}"
	fc_tgt_dev="${fc_tgt_path}/fc_transport:${fc_tgt_num}"
	if [ -e "$fc_tgt_dev/port_name" ]; then
	    read wwpn < $fc_tgt_dev/port_name
	fi
	if [ -z "$wwpn" ] ; then
	    : no WWPN
	    RESULT=1
	    return
	fi
	# Linux currently knows about 32bit luns
	tmp_lun3=$(printf "%04x" $(($fc_tgt_lun & 0xFFFF)))
	tmp_lun2=$(printf "%04x" $(( ($fc_tgt_lun >> 16) & 0xFFFF)))
	tmp_lun1="0000"
	tmp_lun0="0000"

	if (($fc_tgt_lun == 0)) ; then
	    lun="0x0000000000000000"
	else
	    lun="0x${tmp_lun3}${tmp_lun2}${tmp_lun1}${tmp_lun0}"
	fi
	controller_dev="${fc_tgt_path%/host[0-9]*}"

	# FC devices are always endpoints
	d="fc-${wwpn}:${lun}"
	D="$controller_dev"
	RESULT=0
}

handle_block_sas () {
    : handle_block_sas $*
	local DEV=$1
	local cil adapter controller_dev
	# SAS device
	sas_host_path="${DEV%%/phy*}"
	sas_phy_path="${DEV#*/host*/}"
	sas_phy_path="${sas_phy_path%%/target*}"
	sas_phy_id="${sas_phy_path%%/*}"
	sas_rphy_id="${sas_phy_path##*/}"
	sas_phy_dev="${sas_host_path}/${sas_phy_id}/sas_phy:${sas_phy_id}"
	if [ -e "$sas_phy_dev/sas_address" ]; then
	    read phy_address < $sas_phy_dev/sas_address
	    read phy_port < $sas_phy_dev/port_identifier
	    read phy_id < $sas_phy_dev/phy_identifier
	fi
	if [ -z "$phy_address" ] ; then
	    : no initiator address
	    RESULT=1
	    return
	fi
	sas_phy_address="$phy_address:$phy_port:$phy_id"
	sas_rphy_dev="${sas_host_path}/${sas_phy_id}/${sas_rphy_id}/sas_rphy:${sas_rphy_id}"
	if [ -e "$sas_rphy_dev/sas_address" ]; then
	    read rphy_address < $sas_rphy_dev/sas_address
	    read rphy_id < $sas_rphy_dev/phy_identifier
	fi
	if [ -z "$rphy_address" ] ; then
	    : no initiator address
	    RESULT=1
	    return
	fi
	sas_rphy_address="$rphy_address:$rphy_id"

	controller_dev="${sas_host_path%/host[0-9]*}"

	# SAS devices are always endpoints
	d="sas-${sas_phy_address}-${sas_rphy_address}"
	D="$controller_dev"

	RESULT=0
}

handle_usb () {
: handle_usb $*
	local DEV=$1
	cd -P $1
	DEV=${PWD}
	port_id=${DEV##*/}
	port_num=${port_id#*-}
	host_dev_path=$DEV
	while [ ! -z "$host_dev_path" ] ; do
		case "$host_dev_path" in
			*/usb*)
			usb_host_path=$host_dev_path
			host_dev_path="${host_dev_path%/*}"
			;;
			*) break ;;
		esac
	done
	: host_dev_path $host_dev_path
	usb_host_num=${usb_host_path##*/usb}

	cd "$host_dev_path"
	usb_host_offset=$(get_port_offset usb $usb_host_num)
	usb_host_port=$(($usb_host_num - $usb_host_offset))
	cd "$OPWD"

	if [ "$d" ] ; then
	    d="usb-$usb_host_port:$port_num-${d}"
	else
	    d="usb-$usb_host_port:$port_num"
	fi

	D="$host_dev_path"
	RESULT=0
}

handle_block () {
    full_sysfs_path="$SYSFS$DEVPATH"
    if [ -L $full_sysfs_path/subsystem ]; then
	# new sysfs block layout
	full_sysfs_path="${full_sysfs_path%/*}"
	cd "$full_sysfs_path/subsystem";
	subsys="`pwd -P`"
	cd "$OPWD"
	subsys="${subsys##*/}"
	if [ "$subsys" == "block" ]; then
	    # parent is "block", it's a partition, move one up
	    full_sysfs_path="${full_sysfs_path%/*}"
	fi
	cd $full_sysfs_path
    else
	# old sysfs block layout
	if [ ! -L $full_sysfs_path/device ] ; then
	    if [ -f $full_sysfs_path/range ] ; then return ; fi
	    full_sysfs_path="${full_sysfs_path%/*}"
	    : full_sysfs_path "$full_sysfs_path"
	    if [ ! -L $full_sysfs_path/device -o ! -f $full_sysfs_path/dev ] ; then
		return
	    fi
        fi
	cd $full_sysfs_path/device
    fi
    full_sysfs_device_path="`pwd -P`"
    cd "$OPWD"
    D=$full_sysfs_device_path
    while [ ! -z "$D" ] ; do
    case "$D" in
	*/ide[0-9]/[0-9].[0-9]*|*/ide[0-9][0-9]/[0-9][0-9].[0-9]*)
	handle_block_ide "$D"
	;;
	*/css0/*)
	if [ -r $full_sysfs_device_path/wwpn ]; then
	    read wwpn < $full_sysfs_device_path/wwpn
	fi
	if [ -r $full_sysfs_device_path/fcp_lun ]; then
	    read lun < $full_sysfs_device_path/fcp_lun
	fi
	if [ -r $full_sysfs_device_path/hba_id ]; then
	    read bus_id < $full_sysfs_device_path/hba_id
	fi
	if [ "$bus_id" -a "$wwpn" -a "$lun" ]; then
	    # S/390 zfcp adapter
	    d="ccw-$bus_id-zfcp-$wwpn:$lun"
	    RESULT=0
	else
	    # DASD devices
	    bus="ccw"
	    adapter=${D##*/}
	    d="$bus-$adapter"
	    RESULT=0
	fi
	D=
	;;
	*/rport-[0-9]*:[0-9]*-[0-9]*/*)
	handle_block_fc "$D"
	;;
	*/phy-[0-9]*:[0-9]*/*)
	handle_block_sas "$D"
	;;
	*/fw-host[0-9]*/*)
	handle_block_firewire "$D"
	;;
	*/host[0-9]*/[0-9]*:[0-9]*:[0-9]*:[0-9]*)
	handle_block_scsi "$D"
	;;
	*/usb[0-9]*/[0-9]*/*)
	handle_usb "$D"
	;;
	*/pci[0-9]*:[0-9]*)
	handle_pci "$D"
	;;
	*/devices)
	D=
	;;
	*)
	: not handled
	RESULT=1
	return
	;;
    esac
    done

    if [ "$TYPE" == "scsi_tape" ] ; then
	devname=${full_sysfs_path##*/}
	rewind="${devname%%st*}"
	mode="${devname##*st}"
	case "$mode" in
	    *l)
		mode="l"
		;;
	    *m)
		mode="m"
		;;
	    *a)
		mode="a"
		;;
	    *)
		mode=""
		;;
	esac
	if [ "$d" ]; then
	    d="$d-${rewind}st${mode}"
	fi
    fi
    echo "ID_PATH=$d"
}

case "$TYPE" in
    block)
	handle_block
	;;
    scsi_tape)
	handle_block
	;;
    input)
	handle_usb $SYSFS$DEVPATH/device
	;;
    *)
	RESULT=1
	;;
esac
exit $RESULT